Washington mudslide: How did it happen?

At least 176 people have been reported missing in the massive mudslide happened Saturday near Oso, Washington.

http://www.kare11.com/video/3387484767001/1/Washington-mudslide-How-did-it-happenhttp://bc_gvpc.edgesuite.net/img/963482463001/201403/2563/963482463001_3387307866001_0322oso-slide9h-COPY.jpg?pubId=963482463001Washington mudslide: How did it happen?At least 176 people have been reported missing in the massive mudslide happened Saturday near Oso, Washington.vpcbestwa landslidewa mudslidewashington mudslideoso washingtonNational Newsnation now01:43